Analysis of Runoff Simulation under Changes in Climate Variability: A Case Study of the Upper Awash Sab-basin, Ethiopia | Chapter 1 | Geography, Earth Science and Environment: Research Highlights Vol.4

The impact of precipitation and temperature on runoff over land surfaces is examined through runoff simulation analysis. The Soil and Water Assessment Tool (SWAT) hydrology model is used in this study to predict the sensitivity of runoff to changes in temperature and precipitation. To investigate the sensitivity of runoff to temperature and rainfall, these variables were changed. Rainfall and temperature have a major impact on runoff accessibility by affecting the timing and contribution of water sources. For the entire upper Awash Sab-basin (1980–2010), monthly station-based temperature and rainfall data were used to run the SWAT model. The hydrological model was calibrated during an eight-year period (1993-2000), and the simulation findings were validated using historical stream-flow data at the Hombole gauging station's outlet for four years (2001-2005). The calibrated and validated SWAT hydrological model was used to perform a sensitivity analysis in order to evaluate the effect of changes in temperature and rainfall on the sub-basin's runoff. Utilizing the SWAT model, the effects of several theoretical rainfall and temperature scenarios on the yearly runoff of the Upper Awash sub-basin have been examined. This was accomplished by using temperature increases (up to 5°C) and variations in rainfall (+/-20%) separately and in combination. The findings demonstrated that in the studied area, runoff was responsive to variations in temperature and rainfall.  It has been found that a yearly temperature increase of 1, 2, 3, 4, and 50C results in annual runoff reductions of 0.085, 0.88, 1.75, 2.55, and 3.30%, respectively. There is a negative link between temperature changes and runoff, but a positive correlation with changes in rainfall. The findings show that rainfall has a greater effect on runoff than temperature rise. A 10% increase or decrease in rainfall will cause a 22% or 21% increase or decrease in annual runoff. The findings demonstrated that the availability of water was significantly impacted by changes in the climatic variables.

 

Author (s) Details

 

Mekonnen H. Daba (PhD)
Oromia Agricultural Research Institute, Bako Agricultural Research Center, Bako, Ethiopia.

 

Please see the book here:- https://doi.org/10.9734/bpi/geserh/v4/2245